1. Field of the Invention
The present invention relates to hose clamping devices, and more specifically to a hose clamping device in which a diameter of a metallic web band is reduced by rotation of a worm screw, and a flexible hose fitted in and connected to a connector (nipple) is clamped to the connector.
2. Description of the Prior Art
In a conventional hose clamping device using a worm screw, a metallic web band is subjected to punching or embossing to form engaging portions, a housing is fixed to a base of the web band, and a worm screw is supported within the housing so that the worm screw is rotated in its fixed position, the worm screw being rotated to move the web band in a peripheral direction. Such an art is proposed in Japanese Patent Publication No. 22676/1983 and many other publications.
Japanese Utility Model Application Laid-Open Publication No. 161780/1985 proposes a hose clamping device of the type as described above, in which a guide for guiding the web band is provided on the base side of the web band to prevent a free end of the band from being sprung up.
In the above-described conventional hose clamping devices, an operating portion for rotating the worm screw adapted to move the web band is provided only on one side (right side) of a shaft. Therefore, when the worm screw is rotated rightward, clamping takes place, whereas when rotated leftward, loosening takes place. When the operating portion is located in a wide space, no problem occurs. However, sometimes the operation is compelled to be accomplished in a narrow place (space) in terms of execution. At that time, the operation has to be performed in a very tight attitude since the operating portion is present only on one side. For a left-handed person, the rotating direction is reversed, so a problem is given rise to that the operation is difficult to perform.
Moreover, in the case where the operating portion is present only on one side, the mounting direction becomes decided. In the case where the device is set reversely, the band has to be removed and remounted, resulting in an inconvenience in operability.
Furthermore, when the worm screw for moving the web band is rotated, the web band engaged therewith is gradually drawn to reduce the winding diameter, and at the same time, the free end of the web band springs out of an opening of the housing , and spring action is exerted so that the free end of the web band springs up upwardly in an outer diameter direction.
This gives rise to problems that a finger is caught by the sprung-up portion of the web band to get hurt or clothes are caught thereby to cause injury.
In the conventional art for preventing the springup of the web band, the guide for the web band is provided on the base side of the web band. Since this guide comprises approximately L-shaped guide members opposedly provided on both sides widthwise of the band, these guide members function like ribs lengthwise of the web band so as to impair the curving operation of the web band. Accordingly, the expansion and contraction operation in a radial direction cannot be smoothly accomplished in the portion where the guide is provided, thus wanting in proper function of the clamping device which comes into close contact with the outer surface of the hose to uniformly clamp the whole peripheral surface. Separately from the aforementioned prior art, there is sometimes employed means in which a sprung-up portion of the web band is cut after having been completely clamped, in order to overcome a danger as noted above. In this case, there is a restriction that when in reuse, the clamping outer diameter should be smaller than the original clamping outer diameter.